The present invention refers in general to the production of abrasives produced using flexible support media, such as paper, cloth, plastic laminates and similar.
More in detail, the invention concerns a group for joining such closed-loop abrasive belts, of the type including a machine for preparing the end edges of strips of abrasive belt via chamfering, application of a liquid adhesive and drying of the adhesive, and an assembling machine for the said end edges, including a support arm around which the said belt strips are wound in a loop and a press unit for joining the said end edges.
Such groups have been produced and successfully commercialised by the Applicant for a long time. The two machines that form the group have traditionally consisted of autonomous and independent entities, normally installed by the producers of closed-loop abrasive belts in different stations, often far apart. During production, this necessitates manually removing the strips of abrasive belt from the edge preparation machine and transferring them, again manually, to the assembling machine.
This assembling machine may have a generally similar layout to that described and illustrated, even if simplified, in American patent U.S. Pat. No. 5,196,084. In this layout, the support arm of the assembling machine is joined at one end to the structure of the machine; as a result, to effect assembling of the closed-loop abrasive belt, the operator must necessarily close the end edges beyond the fixed end of the support arm, and then move the loop that is formed to the press unit that, when processing is completed, will expel the closed-loop belt that has been produced via the free end of the support arm.
The object of this invention is that of rationalizing the structural and functional layout of the previously defined joining group, rendering the phases of transferring the belt strips from the edge preparation machine to the assembling machine, as well as the operations of introducing the strips around the support arm of the said assembling machine, easier and more practical.
According to the invention, the above objectives are essentially achieved due to the fact that the said support arm of the assembling machine has its input end situated immediately next to and on the extension of the said edge preparation machine.
Thanks to this solution, transfer of the strips of abrasive belt from the preparation machine to the assembling machine is rendered direct and immediate, thereby allowing the group""s production rate to be significantly increased. The production rate can be increased even further by avoiding manual operator intervention for this transfer. To achieve this, a transfer device, which could conveniently consist of an extension to the motorised conveyor belt that the preparation machine is normally equipped with, running to the press unit, could be operationally associated with the support arm.